im Plan erscheint der Zugriff eingerückt unter dem Zugriff auf die Daten der main query, wenn in der Transformation eine push subquery operation durchgeführt wird (sichtbar als PUSH_SUBQ in den outline Hints): "So, as subqueries in a WHERE clause exist solely for producing data for filtering the parent query blocks rows, the PUSH_SUBQ means that we push the subquery evaulation deeper in the plan, deeper than the parent query block’s data access path, between the access path itself and data layer, which extracts the data from datablocks of tables and indexes. This should allow us to filter earlier, reducing the row counts in an earlier stage in the plan, thus not having to pass so many of them around in the plan tree, hopefully saving time and resources."